Square plate shaped magnetite nanocrystals

•Square plate-shaped magnetite nanocrystals were synthesized using arabinogalactan.•Stratification of the particles reduces blocking temperature and exchange constant.•Micromagnetic simulation showed extraordinary magnetization switching anisotropy. Square plate shaped magnetite nanocrystals have been synthesized by chemical precipitation from solution using arabinogalactan. A high crystal quality was observed in the plate plane while, across the plate, there is some stratification. The magnetic hysteresis in such particles is determined by the bulk magnetocrystalline anisotropy, plate shape anisotropy, and surface magnetic anisotropy. It is shown using the micromagnetic simulation that the ferromagnetic square nanoplates exhibit the extraordinary magnetization switching anisotropy, which should be taken into account for understanding the hysteretic properties of the particles.